Endless-track vehicle



P. w. DALRYMPLE. ENDLESS TRACK VEHICLE. APPLICATION FILED APR. I5; 1922.

Patented Oct. 10, 1922.,

I E E H A" s E F. H s 2 P. W. DALRYMPLE. ENDLESS TRACK VEHICLE. .wrucanon FILED- APR. 15. 1922.

Patented Oct. 10, 19220 2 SHEETS-SHEET 2 Patented @ct. l, 1922.

siren sirens l ext 0 PHILIP W. DALRYMPLE, 0F BALTIMORE, MARYLAND, ASSIGNOR- T0 LEWIS K. DAVIS, OF WASHINGTON, DISTRICT OF COLUMBIA.

ENDLESS-TRACK ICLE.

- Application filed April 15, 1922. Serial No. 552,898.

To all whom it may concern:

Be it known that I, PHILIP W. DALRYM- PLE, a citizen of the United States, and resident of the city of Baltimore and State of Maryland, have invented certain new and useful Improvements in Endless-Track Ve hicles, of which the following is a specification.

My invention relatesto an endless track mechanism of the flexible suspension type and has for its object the provision of a mechanism of this character in which the track will readily adjust itself to the surface over which it is assing.

Another object of the invention is to provide means for adjusting the various ropes or cables so that .the track may be kept under the proper degree of tension.

Other objects will be apparent from the following detailed description and the appended claims.

In the drawings:

F igure 1 is a side elevation of the endless track mechanism as a whole.

Figure 2 is a cross section of the upper stretch of the track showing the means for guiding the cables. I

Figure 3 is a longitudinal section of one of the track shoes showing one means for adjusting the length of the cable. 9

Figure 4 is a similar View of a modlfied form of foot and adjustment.

Figure 5 is a section onthe line 5-5 of Figure 4.

Figure 6 is a plan view of a detail.

Figure 7 is a longitudinal section of still another form-of adjusting means.

Figure 8 is a transverse section of the lower stretch of the track showing the relation of the cables and pulleys.

Each side of the vehicle is provided with a pair of vertical plates 1 of horiaontally elongated shape, the edges of which are suitably formed as shown at 2 in Figure 2 to form track-ways for rollers hereinafter described. Track shoes or feet 3 may have tread portions 4 pivoted thereto by bolts 5 as shown in Figure 4, or this separately movable portion may be omitted and the feet formed as shown at 3 in Figures 7 and 8. Where the first form is used, the foot has the appearance shown in the upper part I 10 are'fixed to each of of Figure 2 and the tread may rock from side to side to adjust itself to the surface over which the vehicle is passing.

Each foot has pivoted thereon two rollers or pulleys 6, and links 7 are pivoted at 8 to ears on the feet. Each link has a roller 9 preferably consisting of a pulley between two wheels at its free end, which rollers run on the track 2. A pair of endless cables the feet 3 thus forming an endless track. The particular form of fastening means will be more particularly' described hereinafter.

This endless track member passes around a wheel 11 atone end of the vehicle, which wheel has an axle 12 mounted in an adjustable block 13 whose position is adjusted by means of a screw bolt 14 threadedinto a lug 16 and exerting pressure upon the block 13 by means of an interposed spring 15. At the other end of the vehicle, the endless track passes around a driving sprocket wheel 17 provided with sprocket teeth 18.

The adjacent feet 3 may be separated as shown in Figure 1, or they may lie closer together and have ears which overlap as shown in Figure 4. In this case the ears have registering slots 20 and the cables 10 are connected by bar links 21 similar to those shown in my Patent 1,347,253, July 20, 1920. These links engage the sprocket teeth 18. Similar links are usually employed in the form'shown in Figure 1.

An endless suspension cable 22 normally lies between the series of rollers 6 and the series of rollers 9 as well understood in the art, and tends to keep the vehicle substantially steady even though passing over a rough surface. Each track member has two of these cables, as shown in Figure 2, but as they are duplicates, only one will usually be mentioned. It is desirable to keep this cable 22 under tension but permit it to yield upon sudden shocks, and the following mechanism is provided for that purpose.

A wheel 23 is mounted on an axle 24 in the upper part of the plates 1 and is grooved to be engaged by the cables 10. This wheel is large enough to lift the rollers 6 far enough to separate them from the rollers 9 which continue to run on the track 2 and permit the cables 22 to run free of the rollers. Horizontal pulleys 25 and 26 are supported in any desired manner from the frame (Figure 1). A floating pulley 28 is mounted in a block 29 which also carries a pulley 30 at right angles thereto. A spring 31 is anchored at one end to the frame 1 and at its other end connects to a link 32 in which is mounted a pulley 33. A cable 34 is attached at one end to an adjustable bolt 37 mounted in a lug 35 carried by an arm 36 attached to the frame 1, and the cable passes from the bolt 37 around the pulleys 29 and 33, and thence around a horizontal pulley 38 to the other side of the track where the mechanism just. described is duplicated as shown in Figure 2. Obviously an adjustment of the bolt 37 will vary the tension on the cable 34 and therefore on the floating pulley 29. The cable 22 as it passes over the upper stretch of the track where the rollers are separated, passes around the pulley 25, to and around the floating pulley 30, around the pulley 26, and thereafter between the two series of rollers again. Any variation in tension or pull on the floating pulley 29 will therefore be transmitted to the cable 22.

In a. device of this character, it is desirable that some means may be provided for adjusting the length of the cables 10, in order that any stretch may be taken up and that the endless track may fit its guiding and driving wheels correctly. As shown in Figures 3 to 6 inclusive, this may be accomplished. as follows.

In the central portion of each foot or shoe is a cavity 39 and a block 40 is mounted to slide therein. As shown in Figure 6 this block has a central opening 41 and grooves 42 at its sides in which lie the cables 10 which pass around and under the block.

The block also has a centralopening into' which may be placed a non-rotatable nut 43 preferably rounded on its lower face which is engaged by a threaded bolt 44. The upper edges of the shoe are rounded at 45 so that no undue wear will come on the cables, Obviously a turning of the bolt 44 will move the nut 43 and consequently the block 40 in one direction or the other and thereby vary the length of the cables 10. In order to hold the block firmly in adjusted position, one side of the cavity 39 is inclined as shown at 46 and a wedge shaped member 47 engages this inclined surface. The other side of the member 47 engages the cables 10 and presses them against the block 40. A bolt 48 is screw threaded into the wedge 47, and by turning the bolt 48 in either direction, the wedge may be moved, and the parts thus clamped in adjusted position. In adjusting the parts the wedge 47 is loosened and the block 40 moved to any desired pbsition. Then the wedge 47 is again tightened.

A modified form of adjusting mechanism I is shown in Figures 7 and 8. Instead of the block and wedge, the cavity 39 has two members 49 and 50 each having an outer straight side and engaging inclined sides. The cables pass around these members in a manner similar to that in which they pass around the block 40. Threaded into the member 49 is a screw bolt 51 and threaded into the member 50 is a similar screw bolt 52. By turning these bolts the members may be moved in or out and the length of the cables 10 may thus be lengthened. Since the engaging sides of the members 49 and 50 are wedge shaped, they will tend to retain their adjusted position. Spring washers or a single spring washer 53 may engage the heads of the bolts 51 and 52.

It will thus be seenthat the invention comprises means for adjustingv the length of the connecting cables and also the suspension cables, which means are independent and may be used separately or together. By the means for adjusting the connecting cables 10 at their point of attachment to each foot or track unit, these units may always be kept at uniform distances regardless of the stretch in the cables, and the links 21 may be positioned at the proper distance apart to properly engage the sprocket teeth. Minor changes may be adopted without departingirom the spirit of the invention which is to be regarded as limited only by the terms of the appended claims.

I claim as my invention:

1. Endless track mechanism for vehicles comprisinga series of track units, a cable connecting said units, a suspension cable, means for varying the tension on the-suspension cable, and meansd 'or adjusting the length of the connecting cable.

2. Endless track mechanism comprising a series of track units, endless cables connecting said units, endless suspension cables, means for varying the tension of the suspension cables, and means for adjusting the length of the connecting cables.

3. Endless track mechanism for vehicles comprising a series of track units, a cable connecting said units, a suspension cable, means for varying the tension on the suspension cable, and means by which the length of the connecting cable may be independently adjusted at the point of connection thereof to each of the track units.

4. In endless track mechanism for vehicles including a series of track units and a cable connecting the same, means for attaching the cable to each unit comprising a cavity in the unit, a sliding member therein around which the cable passes, screw threaded means engaging said member to vary its position, and means for clamping the parts in adjusted position.

5. In endless'track mechanism for vehicles including a series of track units and a cable connecting the same, means for attaching the cable to each unit comprising a cavity in the unit, a slidable member therein around which the cable passes, and screw threaded means engaging said member to vary its position.

6. In endless track mechanism for vehicles including a series of track units and cables connecting the same, means for attaching the cables to each unit comprising an opening in the unit, a block slidably mounted therein and engaging both cables, and means engaging said block to vary its position and thereby vary the length of the cables.

7. In endless track mechanism for vehicles including a series of track units and cables connecting the same, means for attaching the cables to each unit comprising a cavity in the unit, a block slidably mounted therein and carrying a non-rotatable nut, said block engaging both cables, and means screw threaded into said nut to thereby vary the position of the block and consequently the length of the cables.

8. In endless track mechanism for vehicles including a series of track units and cables connecting the same, means for attaching the cables to each unit comprising a cavity in the unit, a block slidably mounted therein and carrying a non-rotatable nut, said block engaging both cables, means screw threaded into ,said nut to thereby vary the position of the block and consequently the length of the cables, and means for clamping the parts in adjusted position.

9. In endless track mechanism for vehicles including a series of track units and cables connecting the same, means for attaching the cables to each unit comprising a cavity in the unit, means slidably mounted in said cavity and engaging the cables and also in cluding a Wedge shaped member, and means for adjusting the latter means.

In testimony whereof, I have hereunto subscribed my name.

' PHILIP W. DALRYMPLE. 

